Industrial tractor



Oct. 28, 1941,. E. J. DUNHAM INDUSTRIAL TRACTOR Original Filed Aug. 25, 1959 a Sheets-Sheet 1 Oct. 28, 19 41 E. J. DUNHYAMA' 2,260,804

INDUSTRIAL TRACTOR Original Fil ed Aug. 23, 1939 3 Sheets-Sheet 2 Patented Oct. 28, 1941 INDUSTRIAL moron Elmer J. Dunham, Battle Creek, Mich, asslgnor to Clark Equipment Company, Buchanan, Mich, a corporation of Michigan Original application August 23, 1939, Serial No.

Divided and this application February 23, 1940, Serial No. 320,319

v 13 Claims. This invention relates to industrial tractors,

, and more particularly is concerned with industrial tractors for use-around warehouses, manufacturing and mercantile plants, loading docks, shipyards, and the like where it is desired to transport one or more trailers by means of a power tractor that can draw the trailers from one point to the other, as conditions require.

The present construction contemplat s an entire revision and redesign of industrial tractors of the type shown in the patent to Robert J.

'Burrows, No. 1,715,639, issued June 4, 1929, and

is a division of the copending application of myself and Wayne Gunning, Serial No. 291,526, filed August 23, 1939. c

One of the primary objects of the present invention is: to design a shop tractor of this general character which has greatly increased maneuverability, is more streamlined in appear-' ance, and comprises essentially a knee-action type of front wheel suspension facilitating its travel over uneven roadways in combination with a novel design of steering mechanism for facilitating its maneuvering in close quarters.

Still another feature of the present invention is the provision of a body and frame construction which is designed for mass pr duction, and which requires little or no skill in assembling so that the body, in effect, forms the. chassis for the vehicle and the power plant and driving mechanisms are secured directly to the body assembly to form a unitary construction. This eliminates expensive assembly operations,- and materially reduces-the cost of such machines while at the same time retaining the advantages of simplicity and accessibility of maintenance and repair.

Other objects and advantages of the present invention will appear more fully from the following detailed description which, taken in conjunction with the accompanying'drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

.In the drawings:

Figure 1 is a side elevational view of an industrial tractor embodylng the present invention;

Figure 2 is a perspective view of the power plant and drive axle assembly; I

Figure 3 is a plan view of the body frame and mounting arrangement; and

Figure 4 ma vertical sectional view through the steering mechanism and front wheel assembly.

'Referring now in detail to the drawings, the tractor is indicated generally at 5 and comprises a frame portion 6, a power plant 'I,- a transmisin dotted lines in Figure 1, having carried thereon upon the closely spaced front wheels ill, the

mounting and control of which isdescribed in detail in the above-mentioned copending application. The rear portion of the vehicle is supported on the driving wheels 12 which are geared 4 to the axle assembly 9 to be drivenfrom the power plant 1.

Considering now the power plant and drive axle assembly in detail as shown in Figure 2, the engine 1 may be of any conventional internal combustion engine type, and'has at the-forward end thereof the conventional fan ll which is disposed directly back of a radiator IS. The radiator I5 is adapted to be mounted within the frame 3 by means of the mounting brackets 13 shown clearly in Figure 3, these brackets being secured to the inner surfaces of the nose portion ll of the truck above the motor supporting bracket plate It, shown clearly in Figure 4. The plate 13 is secured to the frame 6 by means of the supporting brackets l9, shown. in Figure 3, to which the plate I8 is secured.

The power plant is provided with the conventional auxiliary mechanisms, such as the generator 20, the distributor 22, the crankcase 23, the starter motor 24, and the oil fill tube 25. Bolted to the rear face of the flywheel housing of the engine is the clutch housing 23,.shown the clutch operating shaft- 21 which, through the arm 28, link 23 and lever 3ll,-is connected to the clutch pedal 32 disposed on the inclined toe board 33 within the frame of the vehicle. The clutch pedal 32 is mounted for pivotal movement about a stub shaft 34 on which is also mounted the brake pedal 35, which brake pedal through the arm 36 is adapted'to actuate the master cylinder 31 of a hydraulic braking system employed on the driving wheels l2.

Bolted to the rear face of the clutch housing 28 is the transmission 8 having t e upwardly extending gear shift lever 39 whe eby the desired change speed ratios through the transmission can .be selected. The driving axle assembly 9 includes a differential having jack shafts extending through the housing arms 40 bolted to the 0 opposite sides of the housing 3 which, at their 5 a forwardly extending boss portion 42 which is ends carry suitable pinions engaging internal ring gears in the wheels l2 for transmitting torque thereto in the conventional manner.

Formed on each of the housing arms" is the-studs 48 shown in Figure 1 whereby these boss portions are clamped about the trunnions '44 carried by the axle supporting plate 48 which is welded or otherwise secured by the angle gus-' sets 48 to the rear end 41 of the frame through the plate 48 which is bolted or otherwise secured thereto. The trunnions 44 are formed on the ends of a rectangular shaft which is welded orotherwise secured to the under side of the plate 48, and suitable trunnion engaging caps 48 and 58 are secured by these studs about the trunnions 44 to secure the axle'assembly to the plate 48. It will be seen that with this arrangement the entire power plant assemblywhich is formed as a rigid unit from the power plant to 2,260,804 suitably tapped to receive the threaded ends of The gear 88 is adapted to be engaged by an ,idler gear 82 carried upon the spindle 83, which spindle is rotatably mounted within a suitable recess inthe plate I8 by means ofthe double tapered bearing assembly 84-.held in position by the bearing cap 88 bolted to the annular retainer collar 88 which is welded or otherwise secured to the upper face of the plate I8. as indi- "cated at 81. This intermediate gear 82 is adapted to be driven from an angularly inclined gear carried at the lower end of a steering shaft 88 which is suitably supported upon the face of the plate I8. The plate I 8 is provided with a suitthe rear axle may rotate a limited amount about the trunnions during assembly. This insures a positive mounting of the .rear axle assembly in the frame.

Disposed above the rear axle assembly 8 is an operator's seat 52 which may be of any conventional-form and which is supported by" means of the angles 53 welded to the rear frame member 41 and the'side angles 54 welded to the sides of the frame adjacent the rear-end thereof. A seat back 55 is also provided, and it will be noted that the side wall of the frame 'is cut away in an arcuate form, as indicated at 88;

with its lowermost point adjacent to the connection between the clutch and the transmission to afford easy access to the operator. The floorboards 88 ofthe tractor are supported. at the rear end by the transversely extending Z-shaped member 88, which is secured at its ends to the angle brackets 88 of the frame, and are supportedlaterally by means of the angles 82 secured to the side walls of the frame. The intermediate portion of the power plant assembly is unsupported on the frame and disposed above the transversely extending T-shaped frame member 84 which extends beneath the flywheel housing, and at its opposite ends is secured to the brackets carried by the side frames of the body 8. In its center the member 84 is formed with an 'ajrcuately depressed portion which clears the corresponding lower arcuate portion of the flywheel housing.

able aperture I88 for receiving the housing assembly at the lower end of the steering shaft, and rotation of the gear (not shown) at the end of this shaft is adapted to rotate the intermediate gear 82 and thence impart rotation to the gear 88, and consequently to the housing 85.

At its upper end -the steering shaft 88 passes through the support I88 bolted to the cowl I81 extending in a vertical plane acrossthe open- The forward end of the power plant is provided with a plate member 88 which is bolted 50 or otherwise secured to the forward end of the engine block, and which is provided with a recessed portion in which the pulley 88 carried at the forward end of the engine crankshaft is received. This plate member is adapted to be secured to the forward cross plate I8, supported on the brackets -I8 and extending transversely across the body adjacent the lower portion thereof. by means of suitable rubber motor supports I8 which are secured between the plate I8 and the plate 88. This provides for a resilient mounting of the forward portion of the motor on the Ody.

' Considering now in detail the frontwheel suspension, which 4; the plate is the body ing in the body, and at its upper end is provided with the steering wheel I88 whereby rotation can be imparted thereto.

Referring again to Figure 4, it will-be noted" that the housing 88 is provided with two opposed downwardly and outwardly extending bosses II8 which are of frusto-conical form, and are adapted to form a seat for the relatively heavy coiled springs II2 extending therefrom. The housing 88 is supported by the tapered bearings H3 and II 4 on the spindle 88, the spindle at its lower end being provided with the nut I I5 for retaining '35 form pivotal support for the longitudinally ex-' tending shaft II8 mounted in a suitable bushing I'll" therein. Mounted on the shaft II Sam the forked ends I22 and I25 of casting members I28 and I21 which carry the-steering spindles I28 and I28, respectively. The forked ends I22 and I25 of tionship on the shaft II8, whereby the shaft I I8 carried at the lower end of the steering housing 85 forms the pivotal support for the steering spindle members I28 and I2 I respectively. Secured in each of these housings, as by welding or the like, are steering spindle shafts I28 and I29, respectively, each of these shafts extending radially with respect to the shaft II 8 and normally in a position inclined slightly downwardly with respeot thereto. Mounted on the respective shafts 6:? which extends transversely across 88 whichis welded as indicated at 82 to the plate and which has an enlarged collar portion 88 'similarly'welded to a recess in the bottom face of the plate, as indicated at 84. Rotatably mounted upon the spindle 88 is a tubular steer- I28 and I28 are the hubs I38 of the forward v wheels I 8 of the tractor, these hubs being mounted by suitable bearings'l32 for rotation about the shafts I28 and I28 and being retained against axialmovement by means of the nuts I34 on the ends of each of the shafts.

lit will be apparent that the steering spindle housings I28 and I21 are restrained against rotation except about the axis of the shaft H8, and therefore they act to allow the spindles I28 and I28. to move about the shaft II8 as a center .in the same vertical plane whereby the wheels I8 can move vertically over obstructions or the like, such as indicated at, I88 in Figure. 4, in which the ,g ,right hand wheel is shown in raised position with I the left-hand wheel in normal position.

Each of the housings I28 and I21 is provided with an upwardly and outwardly extending plate portion I81 and I38, respectively, which plate portions have secured thereto and projecting normally therefrom the rubber bumpers 188 and these members are arranged in alternate rela- Ill, respectively. Extending about these bump era are the springs 2 which are seated on the bosses III of the steering housing .85. It will therefore be apparent that as the wheel ll moves upwardly, the plate portion I38 will move toward the boss portion I III of the steering housing, and will result in compression of the corresponding spring III. This spring normally is of suilicient strength to hold the wheels in the caster arrangement, whereby they are inclined at a slight angle with respect to each other and with respect to the housing 85. However, if an obstruction is encountered, the springs can be compressed and the wheels can move upwardly to a position in which the rubber bumpers engage the bosses Ill and limit further movement. This provides a quiet cushioning knee action construction for the front steering wheel assembly, and insures a smooth comfortable movement of the tractor without imparting any jolts or jars to the operator.

. The wheel-s III are resiliently tired, as indicated at 2, as are also the wheels I2, as indicated at I. If desired, pneumatic tires may be employed, or soft solid rubber tires can be used in situations which do not require the pneu- 'matic tires. The depending arms of the steering housing 85 are preferably provided with downward extensions I45 which limit the possible raising movement imparted by the springs I II to the vehicle when the wheels are resting on the ground to prevent any possibility of a wheel being moved by these springs downwardly into a position in which it would become inoperative.

It will be apparent from this description that I have provided a very simple type of construction in which the tractor body forms the supporting chassis for the power plant and drive axle assembly, and no auxiliary chassis is necessary, The body is also shaped so as to allow close maneuvering, being limited in width to the tread of the wheels I! and having a relatively stiff nose portion I! which can be used for bumping purposes or pushing purposes, the tractor preferably being provided with the coupling mechanism 6 on the rear wall 41 so that trailers or the like may be coupled thereto for towing purposes. The rear wall 41 of the tractorbody extends sumciently high so as to protect the operator from possible injury, and extending over the forward portion of the body is a curved hood I41 which is preferably hinged at its'rear end, as indicated at 8, so that it may be raised for inspection of the engine and for servicing the same with water and oil.

I am aware that various changes may be made in certain details of construction of the present invention without departing from the underlyin principles thereof, and I therefore do not intend to be limited except as defined by the scope and spirit of the appended claims.

I claim;

1. In an industrial tractor, a continuous onepiece body member laterally enclosing the tractor, a power plant assembly including an engine,

clutch, transmission and drive axle coupled to-.

gather as a rigid unit, means for rotatably supporting the axle end of said unit-on the rear wall of said body member, a transverse plate across the forward end of said member, and means resiliently supporting the forward end of said engine on said plate.

a rounded nose portion and having an 'arcuate rear wall portion, the side walls of said body member being cut downwardly from the rear wall to adjacent the center thereof to provide access .into the body member and terminating forwardly in vertically rising edges defining the ends of an instrument panel, and a forwardly and downwardly inclined plate secured to the rear wall adjacent the lower end thereof and terminating forwardly in laterally extending axle housing supporting trunnions.

3. The body member of claim 2 further characterized in the provision of a transverse plate secured in the nose portionthereof having a depending stud and forming a combined steering wheel and power plant support.

. 4. In combination, in an industrial tractor, a unitary assembly comprising a power plant, transmission and drive axle assembly rigidly coupled together, a generally oval shaped body member enclosing said assembly and including a forwardly tapering nose portion, means extending forwardly from the rear wall of said body member including lateral trunnion supports for said drive axle assembly, and means in the nose portion of said body member resiliently supporting the forward end of said power plant for lim-.

ited vertical movement, said unitary assembly pivoting about said trunnion supports to accommodate such movement. l

5. The combination of claim 4 wherein said trunnion support means comprises aforwardly and downwardly inclined plate having laterally directed trunnions at the forward edge thereof, and means clamping said axle assembly about said trunnions.

6. The combination of claim 4 wherein said -means in the nose portion of said body member comprises a transverse plate rigidly secured. to

said body member and a rubber cushioned support between said power plant and said plate.

7. In combination, in an industrial tractor, a rigid assembly comprising a power plant, a transmission and a driving axle, a body member enclosing said assembly laterally, means mounting the forward end of said power plant for relative vertical movement in one end of said body memher, and means pivotally mounting the axle end 2. A body member for an industrial truck of) I of the assembly in the opposite end of said body member.

8. In combination, in an industrial tractor, a power plant assembly including an engine, transmission and drive axle coupled together as a rigid unit, a pair of driving wheels connected to said axle, a body enclosing said assembly and having trunnion means supporting the rear end of said body from said axle, an operator's seat carried by said body above said axle, a trans-- verse plate across the forward end of said body, and means resiliently supporting the forward end of said power plant on said plate.

9. In combination, in anindustrial tractor, a power drive assembly including an engine, transmission and drive axle housingcoupied together as a rigid unit, a body laterally enclosing said assembly, means pivotally supporting said axle housing within the rear end of said body, drive wheels spaced laterally outwardly of said supporting means in the plane of the side walls of said body, means resiliently supporting the forward end of the power plant in the forward nose of said body and allowing limited relative vertical movement therebetween, and steering means secured to said last-named means below the powerplant support.

'plant assembly including longitudinally spaced engine and driving axle connected as a rigid unit.

a generally ovate shaped body laterally enclosing said unit and having a dirigible wheel assembly depending from one end thereof, means resiliently supporting said engine for relative vertical movement; within said end of said body,-and means journalling the opposite end of said body for vertical swinging movement relative to said' to said plate, andmeans rotatably journaling' said body for movement in a vertical plane on the opposite end or said assembly.

12. The tractor of claim 11 further character 2,260,804- 10. An industrlaltractor comprising'a power ized in the provision otawheeled i l rt for said one end of said assembly-depending rrom said plate, and a depending stud secured to said plate and forming a vertical journal for said wheeled support.

13. In combination, in arr industrial tractor, a

power drive assembly including an engine, ,trans-' mission and drive axle housing coupled together as a rigid unit, a body defined by vertical walls laterally enclosing said assembly, means pivotally mounting said axle housing within the ,rear end ot said body, an operator's seat carried by said body substantially above said axle housing, the side walls or said body being cut away to provide easy access to said seat, means resiliently supporting the forward end of, the power: plant in the forward nose of the body. and'a hood enclosing the topo! the forward portion of said body and hinged for verticaimovement at the forward ends of said cut out portions.

- J. DUNH AM. 

